What is somnambulism?
Somnambulism is the formal term for a common sleep behavior: sleepwalking. Defined in sleep medicine as a sleep disorder of the parasomnia family, it describes a state in which sleep and wakefulness occur simultaneously.
Who is more likely to sleepwalk?
Children sleepwalk more than their adult peers and usually “grow out of” this behavior by their twenties.
In children, most sleepwalking is benign and, while the behavior may be unusual, it’s not considered an area of concern by sleep physicians or pediatricians.
Still, some people continue to sleepwalk into adulthood. In this case, they might be experiencing extreme sleep deprivation, another cause of somnambulism.
Other causes of sleepwalking include untreated anxiety, medication side effects (especially the sleep inducing hypnotic, Ambien), the use of alcohol or psychotropic drugs, or other medical conditions (such as seizure disorders).
Sleepwalking happens during nonREM sleep, usually in the deepest stage (stage 3 or slow-wave sleep). For this reason, it can be difficult to awaken a sleepwalker.
Most sleepwalking, therefore, happens in the first third of the night, when stage 3 sleep is most likely to occur (REM sleep, on the other hand, typically takes place during that last two thirds of the night, with episodes growing longer with each cycle).
Is somnambulism caused by acting out one’s dreams?
It’s worth mentioning that parasomnias are categorized as either based in REM or nonREM (NREM) sleep.
This is an important distinction. Sleepwalking and other NREM parasomnias tend to happen outside the confines of dream (REM) sleep (and, likewise, REM parasomnias occur during dream sleep). While dreaming or dreamlike phenomena may also occur during NREM sleep, this is still the exception and not the rule.
Those who experience NREM parasomnias (sleepwalking, but also sleep disorders like night terrors and nocturnal sleep-related eating disorder, or NSRED) don’t normally have recall of their dream content, so it’s impossible to know if their somnambulistic activities are directly linked to dream enactment.
However, some people during active REM (dream) sleep may, indeed, act out their dreams. What’s more, they have complete recall of their dream content. In this case, a different parasomnia, known as REM behavior disorder (RBD), is to blame. This is not sleepwalking, but a behavior caused by a neurological miscommunication that occurs only during REM sleep. Please note: It is never normal to act out one’s dreams.
In normal REM sleep, a “gate” in the brainstem typically blocks signals from the brain to the muscular system (with the obvious exception of the diaphragm, the muscle which regulates breathing). In RBD, the gate malfunctions, leading to dream enactment.
Unlike sleepwalkers, those who experience RBD will awaken fully aware of what they were dreaming. RBD is considered an indicator of neurodegeneration related to Parkinson’s disease and should be investigated and treated.
Is somnambulism dangerous?
Yes and no. It depends upon how deeply asleep and active the sleepwalker is. Much of what they do can be defined as automatic behavior.
In most cases, activities during sleep for somnambulists are limited to simple automatic behaviors and tasks within the space of the bedroom, and these are usually passive and unemotional.
Probably the most common sleepwalking act that people complain of occurs when male sleepwalkers rise to use the bathroom, but mistakenly urinate in a closet, shoe, or corner of the room rather in the toilet.
However, we’ve all heard stories about people (including, and especially, children) walking or jogging or driving from their homes through the streets, into snowstorms, or along steep cliffs with zero knowledge of having done so. Of course, this is dangerous!
Some families install chime alarms on their front and back doors to awaken them if their busy sleepwalking children have left the house at night. Spouses also hide the keys of loved ones intent upon sleepdriving.
It’s important to know that folks with RBD show more exaggerated and dangerous behavior; they experience extreme emotions during their dream enactments and can be physically aggressive and even violent, making them a danger to themselves and others around them.
So, should you awaken a sleepwalker?
There are two schools of thought on this one.
- If the sleepwalker is behaving in a way that is not dangerous to themselves or others, it may be better to leave them be. Often, sleepwalkers are sitting in bed or standing nearby, making odd gestures which, though unusual, aren’t a threat to them or anyone nearby. Let them be; they’ll eventually stop as they transition to other stages of sleep.
- If the sleepwalker is doing things which may harm them or others, a gentle rousing won’t hurt them (contrary to popular opinion, based on a medieval belief that the soul left the body while one slept). But good luck waking them up: sleepwalkers, by the very nature of their sleep staging, are notoriously difficult to awaken. Gently leading them by the elbow back to their bed, even as they sleepwalk, may be your best bet. Safety first!
9 links related to parasomnias in SleepyHeadCentral
- Tex McIver receives 4 guilty verdicts in case involving sleep disorder (Apr 24, 2018)
- Sleep eating, sleep talking and sleep walking (video) (Jan 17, 2018)
- Sleep Fundamentals || L is for Leg Movements (Nov 18, 2017)
- YouTube takes on the use and abuse of the sleeping pill known as Ambien (zolpidem) (Oct 15, 2017)
- Curiouser and curiouser: A year’s worth of unusual sleep and dream stories (May 11, 2017)
- NS-RED and NES, Sleep Eating Disorders (Dec 17, 2014)
- Sleepwalking in the News (Oct 28, 2014)
- Having nightmares? Maybe it’s your prescriptions (Oct 13, 2014)
- Night Terrors (Oct 11, 2014)